Agriculture Reference
In-Depth Information
Disposal of the straw is a problem in some areas of the world. Rice straw has a high
content of silica crystals, making it somewhat resistant to decomposition. Dry straw is
not palatable to most livestock. Many farmers resort to burning dry straw in the field.
This has the advantage of destroying insect eggs and disease spores on the straw. A sig-
nificant disadvantage is the loss of nutrients in the straw and the loss of potential
organic matter additions to the soil. The Connelly - Areias - Chandler Rice Straw
Burning Reduction Act of 1991 in California specified that burning of rice straw be
phased out as an air pollution measure. After 2001, burning has been permitted only
for approved disease control situations. As a result, there has been a surge in alternate
uses of rice straw, such as erosion barriers and home construction.
3.4.11 Marketing
Most rice is consumed in the country of production. Even though China produces large
amounts of rice, it sells relatively little on the international market. The major exporting
countries are Thailand, Vietnam, India, United States, and Pakistan. Many African
countries are net importers of rice.
In addition to the USDA classes, rice is classed by its cooking and food character-
istics. One extremely important classification is the degree to which the endosperm
starch is gelatinized during cooking. Types that cook into fluffy, individual grains are
classed as nonsticky rice. Indica varieties have this characteristic. This is the type
most commonly raised in the United States. Sticky rice has a slightly gelatinous consist-
ency. Japonica varieties normally form a sticky, or mushy, mass when cooked. These
types are very easy to overcook. Glutinous, or waxy, rice cooks differently than the
previous two types. It absorbs less than half the amount of water during cooking but
forms a gelatinous mass. This is used primarily for sweet desserts in Southeast Asia.
Another classification, unique to rice, is that of aroma. All rice has some aroma
released upon cooking. Specific varieties have a slightly perfumed aroma that is
highly prized. One of the best known is the basmati cultivar grown in India and
Pakistan. Although it yields less per hectare, the higher price for this variety makes
it profitable for farmers. Other varieties have been developed in the United States
with similar aromas, one being Texmati.
3.4.12 Postharvest Processing
A 100-kg amount of rough, or paddy, rice goes through a dehulling process to remove
the outermost covering. Dehulling is normally done by machine, but traditional
methods can also be found in small farmer's homes. An example is the pounder in
an Indian village home shown in Figure 3.31. This yields about 80 kg of brown rice
and 20 kg of hulls. The hulls are used as fuel in heating plants, as mulch, and as a
mild abrasive. The next milling, or polishing, stage removes some of the outer seed
coat, leaving the familiar white rice. About 11 kg of by-products are removed in this
step. Of the 69 kg left, only 55 kg passes screening for the market. The remaining
14 kg consists of broken and undersized grains used for brewing and animal feed.
